| ▲ | wewewedxfgdf 2 hours ago | |
>>"We're only allowed to transmit what we have permission to transmit -- and by default, we're forbidden." It is not true that by default you are forbidden to transmit. In fact there are quite open rules in some ways for transmissions. Whenever these discussions about transmission come up there's always people who, without really undrstanding, freak out about transmitting anything and declare that all tranmissions are illegal. Not so. USA hobbyists can legally transmit without a licence under FCC Part 15, but the limits are pretty low and depend on the frequency. AM, up to 100 mW into the final RF stage, with the antenna, feedline and ground limited to a total of 3 metres. FM maximum field strength of 250 µV/m measured 3 metres away. There are special cases, such as 49.82–49.90 MHz, where home-built transmitters can go to 100 mW on a 1 metre antenna. One-off home-built transmitters don't need FCC certification if for personal use not being sold. It's pretty interesting to read if you are a radio head: https://www.ecfr.gov/current/title-47/chapter-I/subchapter-A... https://www.ecfr.gov/current/title-47/section-15.209 "operation within these frequency bands is permitted under other sections of this part, e.g., §§ 15.231 and 15.241." --> 0.009-0.490Mhz 0.490-1.705Mhz 1.705-30.0Mhz 30-88Mhz 88-216Mhz 216-960Mhz Above 960Mhz | ||
| ▲ | ssl-3 an hour ago | parent [-] | |
We're granted permission to make the transmissions you speak of; it is otherwise deny-by-default. This is described right there at the top of your first link, in the first three paragraphs. It's broadly possible to sort any rule (or superset or subset of rules) into one of two different buckets: One bucket contains the rules about the things things we're not allowed to do. Like a firewall with a blacklist, whereby we can do whatever we want that explicitly isn't blacklisted. It is allow-by-default. The other bucket contains the rules about things that we are permitted to do. This is like a firewall with a whitelist, where we can do whatever the whitelist explicitly allows us to do and nothing more. It is deny-by-default. Drug laws in the USA are in the first bucket (blacklisting). Radio transmission rules in the USA are in the second bucket (whitelisting). (There is no third bucket.) | ||